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Any suggestions on reverse engineering a circuit board — Parallax Forums

Any suggestions on reverse engineering a circuit board

Capt. QuirkCapt. Quirk Posts: 872
edited 2007-08-15 09:58 in General Discussion
I have an ignition system board from a company that I worked for from 90 to 94, at which time it went out of business. I have been working on maping it out, off and on for about a year now. And the longer I work on it, the more I have learned about electronics and that board. There is no real control to it, other than the hall effect sensor & reluctor and a set of 555's that control the DC to DC converter. There is also no ignition curve, except for what happens as a result of the rpm increasing and time decreasing. Eventually I want to control it with an SX and finally a Propeller after I know how to fit the micro controllers in.

So, does anybody know if people do this (reverse engineer a circuit board), or is there anybody here that does it. And how much do things like this cost? The board is about the size of a PC-104 format and I have pictures of both sides and maps that I have been·working on in·Photoshop (besides the board itself).

Thanks

Bill

Comments

  • GadgetmanGadgetman Posts: 2,436
    edited 2007-08-13 12:17
    I don't think there are any companies that ofers this kind of service...
    (did anyone say 'Easy target for lawsuit'? )

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  • pwillardpwillard Posts: 321
    edited 2007-08-13 12:35
    Maybe in the far east?

    (Just kidding)

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    There's nothing like a new idea and a warm soldering iron.
  • Capt. QuirkCapt. Quirk Posts: 872
    edited 2007-08-13 15:57
    Why a law suit?, I have no intention to copy it exactly or even close. The company has been out of business for 13 yrs now. I already know what the 3 major circuits are, as they are common published circuits on the net.

    What I don't understand is the how & why (The basics)·of automotive protection circuits.

    Does anybody have an idea about what it would cost to bring my own circuit to an Electronic Engineer and have him/her add the Automotive protections my project would require. (or possibly suggest a book)

    Thanks

    Bill
  • T&E EngineerT&E Engineer Posts: 1,396
    edited 2007-08-13 16:49
    As an electrical engineering co-op intern about 10 years back, I had to reverse engineer a double layer board that was from a higher ranking individual·that had left the company I was a co-op with. The company I co-op'd with thought that he might have taken their design with him. I was supposed to take a volt-ohm meter and basically draw some kind of a schematic or possibly block diagram to compare it with the co-op companies·design.

    I heard that they did take him to court over it and got him to dismiss the design as a copyright infringement.

    Anyway all I used was a meter to check for traces on the board. I tried to first draw out on paper·the parts placement on the board and then draw connection points as best as I could. Start with the Vcc and Ground connections and then move on to the more difficult ones.

    I never got a perfect drawing but had enough information to go to court with.

    Good luck.
  • metron9metron9 Posts: 1,100
    edited 2007-08-14 19:07
    If you can see the traces on the back of the board I take a picture of the front and back, then mirror the back using photoshop and then isolate the components on the front picture stick them together so you can see the components and traces at the same time. looking at the back then flipping it to the front can make your head spin.

    By coloring the back of the board traces one color and the front traces another color when you merge them you can see all the traces. Assuming of course it is a double side board without internal layers.

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    Think Inside the box first and if that doesn't work..
    Re-arrange what's inside the box then...
    Think outside the BOX!
  • FranklinFranklin Posts: 4,747
    edited 2007-08-15 01:02
    What is it that this board does that is so different than something you would design around the SX?

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  • Capt. QuirkCapt. Quirk Posts: 872
    edited 2007-08-15 07:43
    If you can see the traces on the back of the board I take a picture of the front and back, then mirror the back using photoshop and then isolate the components on the front picture stick them together so you can see the components and traces at the same time. looking at the back then flipping it to the front can make your head spin.


    By coloring the back of the board traces one color and the front traces another color when you merge them you can see all the traces. Assuming of course it is a double side board without internal layers.
    I have done all that, and that's why I know what the main circuits are.·I even know all the diode and reistor values (but not all the caps). I could copy it exactly right now. But that's not what I want to do.

    I do want to learn from the board,·why these circuits have been designed with high ohm resitors (pull downs I think) and capacitors to protect it, and·what made·it·reliable product. I have bought several books, but I haven't discovered any info to help.

    Thanks for the response,

    Bill
  • Capt. QuirkCapt. Quirk Posts: 872
    edited 2007-08-15 07:48
    What is it that this board does that is so different than something you would design around the SX?
    They knew how to make a great product and I don't. Features are easy after adding a micro controller,
    Quality and Reliability are not.·It was a quality product that would meet or exceed your expectations, even as it was becoming obsolete.

    (I'm just an electronic hobbiest that want to learn the·how and why, of quality and reliability, to the best of my ability)

    Bill

    ·If anybody wants to be a mentor for a 47 yr old kid, that looks like Shreck.

    Send me a PM

    Post Edited (Capt. Quirk) : 8/15/2007 5:27:14 PM GMT
  • T&E EngineerT&E Engineer Posts: 1,396
    edited 2007-08-15 09:58
    Can you take any photo's of the circuit (front and back) as detailed as you can?
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